Dim the Lights for Birds at Night!
By: Maya Staszelis
Light pollution is another one of the many environmental threats impacting our planet today. But what is
it? Why does it matter? And what can we do about it? Luckily, May 14th is International Migratory Bird
Day, and this year’s theme is how artificial lights at night (ALAN) affect millions of birds migrating
under midnight skies.
What is light pollution?
Light pollution is the brightening of the night sky by our artificial lights at night (ALAN). This excess of
light is harmful to our ecosystems and everything living in them.
Why does it matter?
Many birds navigate by using the stars. ALAN confuses birds resulting in window strikes. These impacts
often lead to injury or death. According to FLAP Canada, a non-profit organization dedicated to reducing
bird death due to window strikes, around 25 million migratory birds die in Canada from crashes with
buildings each year. FLAP also states 1 billion birds die in North America from bird building collisions.
Migration is also an exhausting enterprise. Some birds travel thousands of kilometres, and because they
use natural light by day and stars by night to navigate, excess light does not help. For example, ALAN
obscures the visibility of the stars and alters the flight paths. Birds see city lights from more than 200km
away, flock to them, become confused and eventually fly in circles until they become exhausted and die.
Songbirds, who migrate at night, are especially vulnerable because they call out and attract more
songbirds when they get confused. In short, ALAN increases the amount of exertion birds spend to travel,
taking longer to reach their destination, making them more exhausted.
But, what may be the most concerning is how ALAN changes birds’ migratory paths. These changes are
because many birds are attracted to the light, like moths to a flame. So, more migrants stop in urban areas
with few resources to feed and find shelter, increasing the chances of being struck by cars.
What can we do?
Although all of these facts are concerning, the excellent news is that we can take simple steps to fix the
situation! On an individual level, we can use reflection-free glass with visual markers. That way birds
don’t confuse windows’ reflections with real life. Also, we can follow lights-out programs to protect the
night! The first tip for reducing your light impact is to turn them off when they’re not needed; this is both
environmentally friendly and economically beneficial! Second, install motion sensors on any outdoor
lights. Lastly, use down shields on exterior lights to prevent light trespassing.
Are you still curious about how light pollution is affecting moonlight migrators? Luckily for you, the
Weaselhead/Glenmore Parks Preservation Society is excited to be hosting events for International
Migratory Bird Day! So, come to the Weaselhead, explore your curiosities, and dim the lights for birds at
night!
Watch about dark skies here:
